It has not been possible to provide in a tape-recorder, and especially in a cassette tape recorder, a simple means to interrupt or terminate the recording while the tape is running without recording noise. In certain instances, the mechanical noises which come from the unit itself and which are created by the operation of the "pause" or stop switch are recorded on the tape by the microphone which is built into the unit. Also even with the use of modest recorders it is often desired that the text spoken between the music during a recording of radio broadcasts be excluded without recording the switch noises.
Arrangements are available in high priced recorders to prevent these undesirable cracking noises from being recorded through the use of complicated electronic circuits which can slowly phase out the source of the sound, such as microphone, radio-receiver, etc., in or out.
In lower priced units it has been recommended that the user regulate the sound-level together with the recording-switch however, no suitable mechanical coupling between the recording-switch and the sound-level regulator has been provided.